1. Field of the Invention
This invention relates to light metering systems and more particularly to light metering systems suited for use in TV cameras or the like.
2. Description of the Prior Art
Cameras, such as TV cameras, utilize light metering signals representing either the average or the peak value of the brightness component of the video signal from an image pickup tube. The light metering signal is maintained at a constant level by adjusting the aperture in front of the image pickup tube or the degree of amplification of the video signal. Such conventional light metering systems create the possibility of incorrect exposures when the space of the object being photographed has a particular light distribution, such as occurs when a subject is back-lighted, e.g., a person whose picture is being taken stands in front of a bright background, or when an illuminating light source creeps in the margin of the picture frame. Under these circumstances, the exposure is determined by the bright region of the field so that the subject of principal photographic interest is often under-exposed.